Drug delivery devices are generally known for the administration of a medicinal product, for example insulin or heparin, but also for other medicinal products for self-administration by a patient. Most of the drug delivery devices are pen-type injectors, which dispense a pre-set dose of a fluid medicinal product.
Before the first use of a drug delivery device the user usually has to prime the drug delivery device. Users who are unfamiliar with such pen-type injectors may fail or incorrectly prime their drug delivery device before dispensing the first dose.